Rotary type pump and motor hydraulic transmission



June 15, 1954 2,680,953

ROTARY TYPE PUMP AND MOTOR HYDRAULIC TRANsuzssroN c. I EvANa Filed Feb. 9, 1953 8 Sheets-'Sheet l ATTORNEY? June 15, 1954" c. L. EVANS RGTARY TYPE PUMP AND MOTOR HYDRAULIC TRANSMISSION Filed Feb. 9, 1953 8 Sheets-Sheefc 2 INVENTOR. ARRozLL-Ewq/ys C. L. EVANS Junel5, 1954 ROTARY TYPE PUMP AND MOTOR HYDRAULIC TRANSMISSION Filed Feb- 9. 1953 8 Sheets-Sheet 3 JNVENToR. i4/mal LL,Zl/A/vs June 15, 1954 c. L. vANs 8 Sheets-Sheet 4 Filed Feb. 9, 195:5

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June l5, 1954 c. EVANS 2,680,953

ROTARY TYPE PUMP AND MOTOR HYDRAULIC TRANSMISSION Filed Feb. 9, 1953 8 Sheets-Sheet 5 5 58 r 57 59 M s 48 JNVENTOR. KJ .drf CHRROLLL,EVAN5 f1 "4a BY ATTORNEYS.

C. L. EVANS ROTARY TYPE PUMP AND MoToR HYDRAULIC TRANsMTssIo sheets-sheets Filed Feb. 9. '1953 i INVENTOR. ARRQAAL. VA/v5 ATTORVYS( June 15, 1954 Filed Feb. 9, 1953 l-DRIVER. DRIVER c. L. EvANs 2,680,953

ROTARY TYPE PYMP AND MOTOR HYDRAULIC TRANSMISSION 8 Sheets-Sheet 7 Ld n [E H- (J2-)STROKE H* FULL STROKE. I I Axis ROOVE d GROOVE l 4C /cLG Lw l l@ L Y Y. EL. m S I 5 42 l 44. L l z1- ZLT, Z sad GRoovE/ m5 GROOVEbIHMO STROKE H' FULL STROKE 40 5 'W LN 42 l @jf/+4 2 Jilld 69 n( 8 .3 t4-FULL STROKE /ROOVE X "N aaeGROOVE H'FULL STROKE 66 l L 42 5 L O y: 6 V- 6 '35e E GROOV Axxs 6 l yc-SROoV-I SSH' FULL STROKE IH' NUETRAL Y mj* fn 2 \4-2 L/ 44 4o f GR ove.

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FULL SWING' 'ARRQL/ LJ VANS.

C. L. EVANS June 15, 1954 ROTARY TYPE PUMP AND MOTOR HYDRAULIC TRANSMISSIO 8 Sheets-Sheet 8 Filed Feb. 9, 1953 C FJMJJDB@ 3 E 4 F wf m n 3 E TU lr o 7 .Z f E A. l .n A 5 wm 2M, E In, 1 Y E/ D 2 all Afrox/vaya line II-II of Figure 1, and l t N four cam shafts for rocking the gimbal rings of IX of Figure 4, and

Valong the lines X-X in the device; and is XVIIIfXVII of Figure 1;

and illustrates the other connected to the other seweclempizrtina ring: 5.

Patented `une 15, 1954 UNITED STATES PATENT OFFHICE ROTARY TYPE PUMP AND MOTOR HYDRAULIC TRANSMISSION Carroll'L. Evans, Tipton, Calif. Application February 9, 1953, Serial No. 335,901

An object of my invention is to provide a hydraulic transmission in which any desired speed ratio may be maintained between the drive and driven shafts from a neutral position for the `driven shaft up to an overdrive position with respect to the drive shaft.

A novel manually controlled means is used that includes a lever that may be swung into any desired position between its limits of swing for predetermining the speed ratio between the drive and driven shafts.

It is also possible for the driven shaft 'toA be rotated in a reverse direction to the drive shaft Y. and to rotate at different speeds. The hydraulic transmission is compact in size and is durable Y and eflicient for the purpose intended.

Other objects and advantages will appear inv the following specification, and the novel features of the device will out in the appended claims.

be particularlyy .pointed My invention is illustrated in ing drawings forming a in which:

Figure 1 is a longitudinal sectionthrough the the accompanypart of this application,

f device, portions being shown in elevation and the device is shown in neutral position;

Figure 2 is a transverse section taken along the illustrates oneof the the two units of the fluid transmission ina predetermined manner;

I FSUTES 3, 4, 5 and 6 are transverse sections taken along lines III-III, IV-IV, V-lv and 1 VI-VI of Figure 1;

Figure-7 is a section taken along the line VII- HVII of Figure e;

Figure 8 isA an enlarged detail ofa valve en- A closed in the circled portion VIII in Figure. 4;

Figure 9 is a section taken along the line IX- illustrates a top plan yv iew of the fluid supply device;

Figures 10 to 16, inclusive, are sections taken to XVI-XVI, inclusive of Figure 1. 1

Figure 17 illustrates'the connection between a gimbal ring anda supportingjring;

Figure 18 illustrates a bankpf cylinders; used a section along jthe lline Figure 19 is a side el Figure 2O is also a side 4 Claims. (c1. 6o- 53) Figure 21 is a top plan View of Figure 20 and illustrates the same gimbal supporting ring;

Figures 22 and 23 are sections taken along the lines XXII-XXII and XXIII-XXIII of Figure 18, and illustrates the xed and swingable vanes in the cylinders;

Figure24 is similar to Figures 22 and 23, but shows the movable vanes in a different position in the cylinder;

Figure 25 is a side elevation of the control unit shown in Figure 1;

Figures 26 and 27 are sections taken along the lines XXVI-XXVI and XXVII-XXVII on Figure 25;

Figure 28 is a section taken along the Yline XXVIII-XXVIII on Figure 27;

Figure 29 is a plan view taken along theline XXIX`XYIX of Figure 27;

Figure 30 is a view similar to Figure 1, but shows certain parts in section with the mechanismmoved into a different position from that shown in Figure 1;

Figure 30A is a schematic showing of the iiuid flow;

Figures 31 to 36, inclusive, are diagrammatic views illustrating the position of the parts for diiferentdegrees of rotation throughout one complete revolution; and

of my invention, vit should be understood that various changes or modifications may be made Within the scope of the appended claims Without departing from the spirit and scope of the invention.

In carrying out my invention, I providea casing indicated generally at A in Figure 1. This casing is substantially cylindrical in shapeAL and has its left hand end closed by a header l. The

received. The header 3 also header has an integral sleeve 2 and Figure A30 shows the sleeve 2 extending inwardly into the interior of the casing and rotatably receiving a drive shaft B. The other end of the casing is closed by a header 3 and this header has a central bore 4 in which a driven shaft C is rotatably cess 4a which is concentric which communicates therewith.

It Will be seen from Figure 30 that the. drive shaft B has an enlarged cylindrical portion Bl,

that isprovided with a bore 5, this bore having itsaxis coinciding with thelongitudinal axis of the driveshaft. Still referring to Figure 30, it

connection between thehalves extend from. a disc 2-I will be seen that the forward end of the driven shaft C is rotatably received in the bore 5. The driven shaft has an enlargement that constitutes one part of a revolvable cage D. The enlargement indicated generally at 6, and which is integral with the driven shaft C, has a ball bearing race I separating it from the inner end of the enlarged cylindrical portion Bl ofthe drive shaft B. The portion CI of the driven shaft C that is rotatably received in the enlarged cylindrical portion BI of the drive shaft, may be operatively connected to the drive shaft in a manner now to be described.

In Figure 18, I show the enlarged'cylindrical portion BI of the drive shaft B provided with four radially extending cylinders E, the axes of these cylinders lying in a plane which is at right angles to th-e longitudinal axis of the drive shaft B. The individual cylinders are spaced 90 from each other. Each cylinder E. has its interior 8 communicating with the bore 5 of the enlarged cylindrical portion BI, bya passage Iii. A cover I I for each cylinder E has a central opening I2 for rotatably receiving a stem I3. The stem is integral with a rocrable vane I, see Figure 22, and this vvane is free to rock. within the cylinder interior 8.

It will also be seen from Figure 22 that the cylinder E has inwardly extending and diametrically opposed stationary vanes I5. ner ends of theY vanes I5. carry sealing strips It that contact with the outer surface of the stem I3 that projects into the interior ii of thecylinder E. The two rockable vanes I@ are integral with the stern I3 and are V.liametrically opposed to each other as shown in Figure 22; The outer ends of the vanes Iii carry sealing strips I'I that contact with the inner surfaces of the cylinder E so as to provide a liquid tight seal. In Figures 22 and' 23, it will be seen that the vane Ilia has a passage I that leads from the right handside of the vane in Figure 22 to the left hand side of the vane Ilib, so as to place the compartment El in Figure 22 in communication with the compartment E2 fora purpose hereinafter described. A second passage I8, seeFigure 23, extends from the left-hand side of the vane 14a to the righthand side of the vane Illb so as to place the compartment E3 in communication with the compartment Eli. ways I8I9 will be explained hereinafter.

I wish to rock the rotatable vanes Ma. and Ib in a particular manner in order to eiect Va variable connection between the drive shaft B and the driven shaft C. The variableconnection is ac- 'complished byy means of a iiuid which is fed into the compartments El to E43, inclusive, in a manner hereinafter descri ed for forming a hydraulic drive and driven shafts B and C. Before describing the conveying means for the iiuid toand from vthe compartments E to E4, inclusive, I will irst describe how the vanes lila and Ilib may be swung in a predetermined l manner between the stationary vanes I5.

Figure 18 shows the outer ends of the stems I3 in the horizontal 'cylinders E being connected by a gimbal ring'F to two vertically arranged trunnions 2S. InjFigure 19, vI illustrate one of the horizontal cylinders E in lFigure 18 as'facing directly forwardly and I showhow the stem I3 is connectedto lav gimbal rin'g two d-iarnetrically opposed verticall trunnions 20. The gimbal ring F is in reality-formed of two halves indicated at FI and F2 in Figure 18. `These The purpose of the dual passagey F'. I further show' how this gimbal ring F is connected to one of the zcylinders E with these trunnions.

- ings asthe parts are shown.

4 projecting end of the stem I3, see Figure 18 and extend to the bearing members .22 which in turn rotatably receive the vertical trunnion 20, see also Figure 17. The trunnion 29 is integral with an internal ring G, see Figure 19, that is rotatably mounted within a channel-shaped and rotatable thrust bearing H, see Figur-es 14 and 15. The internal .ring G carries Atwo trunnions Zuwhich are diametrically opposed toeach other. and the gimbal ring F connects the discs 2l on the horizontal The reference to vertical trunnions 20 and horizontal cylinders E is only-for purpose of designation in the draw- Of course the cylindersEand the internal ring G, will be free to rotate about the longitudinal axis of the drive shaft B' and'thereforev-the cylinders and trunnions 20 will be constantly changing the vertical cylinders screws Zia., -seerFigure their positions. Again referring to Figure 18, it will be seen that E have their exposed stems A second gimbal ring J is connected to the two dics'c 23 and isv rotatably secured to two horizontal trunnions 2li that aredisposed 90. away from the two verticall trunnions 2&3." The horizontal trunnions 2,4 are indicated in Figure 21 as being integral with a second internal ring K that is rotatably mounted within `the channel-shaped thrust bearing H. VBall bearing races 25, 25 and 21 separatethe internal gimbalsupporting rings G and K from eachother and from the side walls of the channel-shaped groove in the thrust bearing H; The result is 'that the internal-rings G and K are free to rotate Within the channel-shaped'thrustbearing. `The channel-shaped thrust bearing H is of the shape shown irl-Figures 14` and 15.V The two identical halves of this bearingareheldA together by cap 19; The thrust bearing H can rotate and it can be swung into angular positions, compare Figure'l-with Figure 30. The

I3 ,keyed to discs 23;

' mechanism for accomplishing thiswill now be described.

In Figures 1 and 15, I show the channel-shaped same gears 29. section in Figure 1 and -a rectangle, see Figures nions 28 that are diam-etrically opposed to each other; and extend' outwardly Yfrom the bearing.

-Gears 29-,are keyed tothe trunnions 28, see Figlures 14 -and15, so that a rotation ofthe gears will-rockthe thrust bearinginto the-desired angular position. The two halves ofthe thrust bearing H have their outer edges in the shape of 14 and lgiwhile-the rim of the annular groove that receives-the rotatable rings G and K,vforms the edge of a large opening within which are disposed the cylinders E.

In Figure l,I-show.the'sid-e elevation of the thrust bearing H', and I further show on-e of the horizontal trunnions 28 and one of the gears 29.

vThe trunnions 2S are rotatably `received. in bearings in the rotatable cage D; 'Thepurpose of the 1 cage is `not only to supportthe thrust bearing H with its ytrunnions 28 and its gear 29, but also to support a control mechanism for swingingthe thrust plate I-I into-the desired angular position.

Again referring to Figure 1, itwill be seen that the gear 29 meshes'with anuppervworm sleeve 'l' 30 and also'with a lowerworm sleeveA 3|.-r There are two upper sleeves 30,s'ee Figures 14- and 15, and their worm portions 30a mesh withr the upper i portions ofthe gears 29. f In likernanner there are two lower worm sleeves 3l andtheir worm portions 3Ia mesh with theA lower portions of the The worm sleeve 3i)v i's-shown in itwill be seen that it is rotatably mounted in the frontand middle-inembers 32 and 33 of the cage D. The cage-mem bers 32 and 33 have recesses'32a and 33a`ior rotatably receiving the ends of the worm sleeves 3D.

In like manner, the worm sleeves 3i are rotatablyy their forward ends rigidly secured to a sleeve 36,

see Figures 1 and 10, so the shafts will be held against rotation about their own axes. The helical screw shafts can be moved in the direction yof their longitudinal axes. ported by and slides on the outer, surface ofthe stationary sleeve 2 in which the drive shaft LB rotates. A yoke 31 is connected to the sleeve 36 so -as to move it along the stationary sleeve 2 While permitting the sleeve and the helical screw Shaftsto rotate with the cese-, D- The yoke 31 desnot rotate, see Figure 30. A Y

Before describing the mechanism for moving the Ayoke 31 on the stationarysleeve 2 it is best to set forth at this time that each of the helical screw shafts 34 and 35 is provided with a helical groove 38 of the type shown in Figures 1 and 15. The helical groove 36 hasashort forward helical portion 38a andthen this portion merges into a longitudinallyextending portion 38h followed by asecond helcalprtcn.iig- Pins 39, See Figures I and lare carried by theworm sleeves 3i! and have their inner ends slidably received in the helical grooves 38. Whenthe thrust bearing H is in neutral position,A i.b e., th-e vertical position shwn in Figurel, the p ins 3Q will be received in thelongitudinal groove portion 38b. When it is desired to swing thethrustbearing H in a eleganter-clockwise direction about its trunnions 26.the yoke, 3l is, movedto. the right by va means hereinafter described and this will move the helical screw shafts 34 and 35longitudinally to cause the pins 39 of the worm sleeve 39 and;3l to move into the front helical portion 38a. Since the helical screw shafts 34 and 3 5 cannot rotate, the helical groove portions SBaYvviILimpart a, rotative movement to the worm sleeves 36 to cause, them andlc for rotating thegears 29 in a counterclockwise direction when looking yat Figure l1.

When this movement takes place, the thrust bear-V ing'H will swing in a counter-clockwise direction and will bemoved fromuits neutral position into Va forwardly inclined position. The result of such movement will operatively connect the drive shaft B` withthe driven shaftC and this will be eX-V plainedhereinafter.

It is best now to set forth the mechanism for moving the yoke 31 and rotatable sleeve 3E along the stationary sleeve 2 in the desired direction. Reference to Figures land 11, shows the yoke 31 connected to two piston rods 40 and 46c and these rods are slidably received in closure members 4| for"'cylinders indicated generally at L and LI. Each piston rod Mland 46c has an integral piston head `42an'd 42d and the rod 4U is made hollow as at"43` for the' greater portion of its length. A rotatable shaft`A 44 is rotatably received in an opening '45 that extendsthrough the otherwise closedend of the cylinder L. The shaft 44 has helical grooves 46 thereinand thepistOn head 42lias keys 4l'ektending'inwardly into the bore 43 4and being slidably received in the helical grooves 46.

There are two helical screwshafts The. Sleeve 36 is sup-V..

The resultis that whenthe pistonv head42is moved within the cylinder Lthe shafts mounted on the top cf the shaft to rotate there;

Within 6 44 will be rotated. The cylinders'L and Ll are disposed at opposite sides of the housing A, see Figures 1, 10 and 12, and an arcuate conduit 4Ia. interconnects the interiors of the two cylinders. In Figure 3 a cross sectional view through the piston head 42 is made and clearly shows the inwardly extending keys 41 that ride in the helical grooves 46 of the shaft 44, see also Figure 13.

The means for moving the pistons 42 and 42a in the cylinders L and LI, will now be described. In Figure 1 the rotatable shaft 44 is shown provided with a bevel gear 43 and this gear meshes with another bevel gear 49 that forms a part of a control mechanism M shown in elevation in Figure 1 and Asetforth in enlarged sectional detail in Figures 26, 2'7 and 28. Figure 26 is a horizontal section through Figure 25 and a high pressure line 50 leads to both ends of a cylinder 5I. Within thecylinder, I mouni-l areciprocable valve M I, see Figure 26, and this valve has a head at each end ldesignated at 5,2 and 53. At the centerof the n elongated valve Ml, I provide rack teeth ,'Mwhiclp are circular in shapeand are larger in diameten than the reduced intermediate portion of the valve.

THQ rack teeth imesh with eearteetli. 5i

formed on a ring 55 that is adapted to rotate about;

@vertical .aXS- .Figurel Showsthe rineasbeins..

Cup-Shaped in veltialsetionand.this rinehas.,

a tubular dependnaportion. 5.1 innhicli aralrc, shutoff Shaft 581s keyedse ea1SO Fsure 2Q-...she shaft 56 carries the bevel gear k4 6 at its lower end that is in mesh with the bevel gear, 48 b Again referring to Figure 21,itwillbenseenthat theV ro;A4

tatablering 56 carries inwardly extending bosses 59 that are disposed ,diametrically apart as .lear ly shown in both Figures26and27, andthe bosses rotatably carry idler bevel gears. bevel gears 66 mesh with abevel gearlthat is with. The rotatable ring 5S is disposed M a housing 62 and a closure plate v63 covers the, top of the housing and is providedwith a bore in which a valve control shaft 64 is rotatably, mounted. Figure 27 shows ythe shaft 6 4 carrying a ,bevel gear, 66 at its lower end andthis gear meshes with both idler bevel gears. tion of this structure is to act as a connection between the Valve.control-shaft,564v and the valve shutoff shaft 58.

The valvecontrol shaft 64 is manually rotated by a shifting lever 66, sible to swing vthe shifting lever 66 into anydea sired angular positionand a projection .5 1y carried by the underside a plurality of radially extendingteeth 68 formed on a disc 69, see Figures 28 and 29; also thesehe; matic viewsin Figures 37 and 41. mounted on the top of the housing 62 and siecured Vto the vclosure plate 63 so as to,be.held, against rotation. The swinging of v theleverl will rotate-the shaft 64. It is best to describe.A

other parts of the mechanism before setting forth verticali durerenum see Figure 27. It isaposf,v

of the. leverwill ride over;

4'I'he disc I is.v

will be seen that aeeogeseif der and this pipe Vcommunicates-with:anlannugV lar groove disposed on the interior of the cylinder 5|. The'pipes 12 and Hare shown in Figurel as yextending from `the valve cylinder y5| to opposite ends of the vcylinder L. The pipe .1|| communicates with the left-hand end of the cylinder and the pipe 12 communicates with the right hand end of the same cylinder. seen that when the reciprocable valve MIv is shifted to the right in Figure 26, by the teeth f55 on the ring gear B2, the left-hand valve head 52A will uncover the annular groove 13 and permit fluid from the high pressure line 59 to pass into thepipe 12 and bev transported to `the right-hand end of the cylinder L for moving the piston 42 to the rleft inFigure l. A pipe a places the right vhand end of the cylinder L in communication with the right hand end of cylinder LI.

The fluid trapped on the left hand side of the pistons |12 and 42a during their movement to the left, will flow from the cylinder L| through the Ipipe 4ta, and through the pipe 14 from the cylinder L, to enter the interior of the valve cylinder 15| between the valve head 53 and the teeth 54 because the valve head 53 has been moved to the right in Figure 26 and has uncovered the annular groove 15 to the interior of the cylinder 5|. The valve head 53 prevents any communication :between the uncovered'annular groove 15`and aA branch pipe a that communicates with the high pressure line 50. In Figure 26, I show Vthe return or exhaust pipe 16 communicating with the interior of the housing 52. There is enough space between the rotatable ring and the housing 62 to permit fluid flowing into the interior of the cylinder 5| to find its way between the rotatable .ring 5E and the housing 52 and pass out through :the exit pipe 16. In this way the flow of fluid to .and from the cylinder L is controlled by the reciprocable valve Ml and the position of the valve in the cylinder 5| determines which way the pistons 42 and 52a will be moved in the cylinders L and Li. When the reciprocable valve MI is in neutral position, the valve heads 52 and `53 will cover the annular grooves 13 and 15 andY prevent :any fiowfof fluid into or out of the valve cylinder.

.'Ihe parts are shown in neutral position in Fig-r ure 2 6 the cylinders E so that the interior of the cylinbe kept filled with fluid at all times. In Figure l, I show an automatic relief valve indicated generally at N and Figure 4 shows the relief valve Nin longitudinal section on a larger scale. The valve N comprises a housing 11 and this 'housing has a depending pipe 13 disposed at one end'of the housing and extending down into ay fluid reservoir P provided in the lower part of the'casing A, see Figure 7. A check valve y19 is placed at the lower end of the pipe 18 and permits a flow of fluid in one direction only, and that is from the reservoir P up to the interior of Vthe housing l1.

A second pipe communicates with the interior of the housing 11 at the opposite end from fthe pipe 18 and this pipe has a check valve 8| placed at'the entrance end. Figure 8 shows the check valve 8| on a larger scale. Both the pipes y18 and 80 are for the sole purpose of conveying liquid from the reservoir P into the valve housing 11 to make up fluid loss due to leakage. A central pipe 82 communicates with the center of .the housing 11 and its purpose is .to the reservoir P from the interior of the cylinders will der 11 when the device is overloaded.' FigureAy It will beV -to return fluid' showsthe central pipe 82 communicating with ank annular groove '83 that is provided ontheinterior of the cylinder 11.

A floating valve body or piston Ni is mounted within the cylinder 11 and may be moved to the` right -or left within thecylinder. The normal position of the valve body or piston NI is'illustrated in Figure 4 where it will close off the anlnulargroove 83.

compression is adjusted to the desired point by adjustment screws 9Sfand-81. The adjustment is such as to hold the valve body or piston in the center of the cylinder 11 when-the motorsE and R needno fluid as clearly illustrated in Figure 4.

The fluid controlled by the relief valveN is placed in communication with the interior of the cylinder by pipes 88 and 89, see Figure 9, that communicate with the interior of the cylinder -11 closing a portion of the driven shaft C, see alsov 90 provided on the Q communicates with ai Figure 6. The annular interior of the sleeve passage 9| provided in the driven shaft C. The other pipe 89 communicates with a secondA annular groove 922 provided in stationary sleeve Q, see Figure 5. The annular groove 92 communicates with a secondV passage t3 pr'cvidedin the driven shaft C. The passage 9| and 93 parallel eachother and extend forwardly along the shaft C vdistance to crossover branch passages yIllu and Sita, see Figure 30; The passages 9| and 93 then extend forwardly in parallel relation from the .crossover passages `Slot and .of )crossover passages i9|b and 9311.`v `The branch Ipassages 9|b and 93h are associated with the cylinders E, already described, and form part of the fluid transmission B andthe'driven shaft C. The branch passages lSia. and 93a are associated with a second fluid groove fixed sleeve Q. Between the passages 9|b and `.93h in Fig. 18l valve-like projections 93e are' formed in the shaft C and close and open passages l0.

In Figure 30A, I show in a schematic way, the path taken byV the fluid from the uid reservoir P, through the inlet pipe 18 of the relief valve N, Ithe pipe 88 to the passage 9|, branch Sla, the continuation of the passage 9|, and thence to the crossover branch-SIU to the front group of cylinders E. The fluid returns 4back through the crossover branch 93D, passage |93, to the crossover branch 83d, the continuation `of'the passage 93, and then to the relief valve N, by means of the pipe 89. The fluid entering the relief valve casing 11 will move the valve body NI and cause the'fiuid to return to the reservoir P by way of the pipe 82. The movement of the Nanes hli in the cylinders E will cause the iiuid to flow in a particular manner to a second group `of cylinders R as hereinafter set forth. The relief valve N merely keeps the passages and compartments filled with fluid and relieves any excess fluid.

The crossover branches l9 la and A8301. have ports at their ends communicating'with a second group ofi cylindersR'and vanes of the same constr'uc- Coil springs 84 and 85 bear against opposite ends'of the valve body and their the interior of the for va predetermined 93a to a secondset*y between the drive shaftV the crossover K 9 tion as the cylinders E and the vanes I4. This second group of cylinders and associate parts will be briefly described -before the operation of the device is set forth. In Figures 1 and 30 a second channel-shaped thrust bearing HI is shown :placed between the middle member 33 of the cage D and a rear member of the same cage, The middle member 33 of the cage is integr-al with the driven shaft C, see Figures 1 and 30. The front cage member 32 Trotates on ball races |0| and |02 that are placed between the member and the end of the sleeve 2, and between the member v -32 and the drive shaft B. The rear cage member |00 rotates on the stationary sleeve Q, 30, and a ball bearing race |03 supports the rear member in an antifriction manner.

The second channel-shapedthrust bearing HI is shown in both Figures 1 and 30 as being tilted so as to be inclined towa rd the right. The thrust I'bearing HI can be swung about horizontal trunnions ZBa'to the right or to the left from neu- `itral position, in the samemanner as the thrust bearing H, with its trunnions 28a are rotatably :carried by the rotatable cage D and may be swung to the right or left from neutral position. vThe trunnions 28a for `the thrust bearing I-II, have' gears 29a, see Figure l, that are keyed thereto and these gears are in mesh with two worm sleeves |04 and two worm sleeves |05, that are similar to the worm sleeves 30 and 3|. The iworm sleeves I 04 and |05 have worm portions |04a and I05a that mesh with the two gears 29a, andthe wormsleeves are rotatably carried by the'middle and rear cage members 3 3 and |00. The helical -screw shafts 34 and 35, shown in Figure 1, not only extend through the pairs of =wormsleeves 30 and 3|, but they also extend vthrough the additional pairs of worm sleeves |04 and |05. The helical grooves 38 inthe two shafts 4 and in the two shafts 35, have longitudinally "extending portions38d that extend from the rear end of the second helical portion 30e, on to a third helical portion 38e that is received within lthe worm sleeves |04 and |05. The third helical *portion 38e merges into a short longitudinal lpor- 'tion 38j and terminates in a fourth helical por- ,tion 38g. Pins 39a, see Figures 1 and 2, are car- "ried by the worm sleeves |04 and |05, and are "received in the longitudinal portions 38d of the grooves 38.

YThe helical groove portion l30a stands for Reverse; the straight portion 30h stands for Neutral; while the helical portion 38e stands for Half Speedforward So long as the pins 39 are in the will remain in the straight grooves 33d. The helical groove portion 38e stands for 1:1 ratio be- --tween the drive shaft B and the driven shaft C yand the helical groove portion 38j stands for Overdrive When the pins 30a. are in the heli- '.cal groove portions 30e and 30g, the pins 39 will be received in the straight groove portions 38d. The parts are shown in Neutral position in Figuresv 1 and 38, while in Figures 30 and 39, the parts are shown in half speed forward position, although there is always a hydraulic connection between the drive shaft B and the driven shaft C. 4When the pins 39a are in the position shown fin Figure l, the thrustbearing H will be inclinedv 1 to the right in this figure, which is the equivalent to a full stroke being effected by the vanes |00, see Figure 30, in the second group of cylinders R for each revolution of the drive shaft B. However, the device will be neutral because the fthrust plate H will be neutral. The pistons-'42 see Figure the right-hand thrust 10 and 42a will be positioned one-sixth the dis- .tance from the right hand-ends of the cylinders L and Li, see Figure 38.

Returning to the second thrust bearing HI and its associate parts, there are four radially extending cylinders R for the stationary sleeve Q just as .there are the four cylinders E for the rotatable drive Iportion BI, see Figure 30 where two of the 'cylinders are illustrated for each bank of cylinders" E 'and' R. Each cylinder R-has -a stem |3a that is 'axially aligned with the cylinder and carries the radially extending vanes |06, see Figure 30A. Stationary vanes |01, and shown in section lin Figure 30, extend inwardly from the inner wall of the cylinders R and bear against the rockable *stems "13a in the same way as the vanes I5 shown in Figures 22-24, inclusive, bear against the rockable stems I3.

The first thrust bearing His shown in vertical or neutral position in Figure 1, and this is "when the pins 39 are'received in the longitudinal portions Y,38h of the? grooves 38.

If the helical 'screw shafts 34 and-35 are moved to the right in Figure 1, as far as possible, the thrust bearing H will be rotated clockwise about the trunnions123 into ra position somewhat similar to bearing H I, except the thrust plate l-I will be in one-half stroke position, see Figure 37. The-.pistons 42 and 42a will be `at the extreme right endsrof the cylinders L and LI. The right-hand lthrust bearing Hl will remain in the position shown in Figure 1 during this movement because the pins 39a will merely slide along the longitudinal groove portions 30d. When the thrust bearing His inclined to the right,` the Ydrive shaft B Y`when making one revolution will cause the driven shaft C to rotate in a reverse direction.

vFigure 30A illustratesthe fluid ilow'through the variousV parts'when the' device isplaced in Reverse position as schematically indicatedin Figure 37. The drive shaft B, not shown Yin .Figure 30A, will rotate counter-clockwise when' looking from the left-hand end of Figure 30A, and

the drive shaft Cwill be rotated in a clockwise cage D will also rotate in a clockwise direction. The thrust of the gimbalring J against the thrust bearing H will give @counter-clockwise thrust to the bearing.

Thel -higl 1f1:' ressure of the iiuid in the compartment El produced by the vane Hic swinging to the right,'"will cause v a high pressure working Yiiowof uidto move through the passage 9| tothe-vane |0641.` to Athe right.r-

ward the group offcylindes RL A high pressure working flow of 'fluid is established in the compartm'ent R3 in one of the cylinders R to swing The high pressure Yarea will also establishitself in the passage 9| fthat connects with the pipe 80, but in this passage there will be a high pressure vibrating flow as indicated lby the "arrows pointing in both directions for the passages 9| and 80.

vThere will be no uid'low through the pipe A low pressure vibrating ow of fluid will .v take place in communicating passages 83 and 93 and thisvis indicated in Figure 30A by the arrows ,pointing in both directionsfor these passages. The thrust of the gimbal ring J associated with the cylinders R, will give a clockwise thrust to f the lthrustJ bearing I-II.l A full stroke will be imparted to the thrust bearing HI while only a half stroke is imparted to the thrust bearing H.

The fullstroke of the thrust hearing HI therefore. overcomes the half stroke-ofthe-thrust haarh1 ing H and the cage D will therefore be rotated in a clockwise direction.

A low pressure idle flow of duid will rnove along thepasage 23 from the cylinders R to the cylinders E as indicated by the arrows Figure 30A. The driven shaft C will ce rotated in an opposite direction to the drive shaft B and the device is therefore in Reverse position.

Neutral position is illustrated in Figures l and 38. The drive shaft B will rotate counterclockwise and there will be no rotation of the driven shaft C. There will he no the passages 9| and 93 because the ow of fluid through plane of the thrust plate H will be perpendicular to the axes of the drive and driven shafts. The

only time fiuid will be discharged from the pipe 62 is when the device is overloaded. trate the position of the lever (it for Neutral positions.

Figures 37 and 38 illus- Reverse and A movement of the helical screw shafts 34 and 35 to the left from the position shown l, will move the in Figure device into forward Half Speed.

The pins 3S will ride from the longitudinal groove portions 38h into the helical por tions 38o and the thrust hearing H will be swung into the in- The rightin its in- Figures l be moved to the centers of the cylinders L and Ll to effect this movement. The thrust bearings H and l-Il will be inclined in opposite directions and therefore the input shaft B will rotate twice as fast as the driven or output shaft For the Half Speed forward position C, see Figure 3Q.

of Figure 39, the drive shaft B will rotate counterclockwise.

The thrust plate E and Tri. full stroke.

will each have a The high pressure working flow will be in the portion of passage 93 that connects the uid pressure in compartment E4 with the fluid pressure in compartment R2. in this passage will The actual nuid be from the cylinders E to the cylinders R or just opposite from that indicated Y in Figure 30A.

The idle low pressure fluid flow will be in that portion of the passage Sl that extends from the compartment R3 to the direction of Vflow illustrated in Figure 39A.

the compartment El, and will be opposite from that The portions of the passages 9i and 93 that connect with the pipes 88 Vand 89, respectively,

inboth directions. There will he no will have the vibrating iiow fluid flow in pipes se and 82 and only sufficient flow in pipe T8 to make Yup any deficiency.

The thrust Von the gimbal J clockwise thrust on the the other girnhal associated with the will Ygive a counterplate H; The thrust of plate H l will give a counterclockwise thrust to this plate.

YThus there are Ytwo equal thrusts on the cage D and this will counterclockwise cause the 'driven shaft C to rotate counterclockwise at onehalf the speed of the drive shaft B. drawn from the cylinder E to supply ders E. Figure 39 illustrates Fluid is the cylinthe position of the A lever t for Half Speed forward position.

A still further movement of the helical screw sha-f Vs and 35 to the left beyond the positions shown in Figure 30, will move the pins 39 into the longitudinal groove portions 38d,

third helical portions Vmove the pins SSainto the swung into neutral position and the The right-hand thrust bearing HI and will will be left-hand thrust bearing H will remain in the inclined position tojthe left as illustrated. The pistons d2 and 32a will have been moved to one -siXth the hand end. The parts will Ytion. For each turn of Y along the longiti Y tion, will be the same Yments Rt and l2 'length of the cylinders L and Li from the leftbein Direct Drive posithe drive shaft'B, the driven shaft C will make one-turn, see Figure 40. For the Direct Drive or the 1:1 ratio position, the rotation of the drive shaft will 'ne in a countercloclzwise direction, The thrust Vof the gimbal J will give a counter-clockwise thrust against the plate No fluid will be drawn 01T by the cylinders R from the cylinders E because the thrust plate El will he in neutral position. There will therefore be no -iiuidfiow of either high pressure in passageY t3 Yor-low'pressure in the passage i, and also no new in the pipes S8 and 8i). The cage D and the driven shaft C will he driven at the'sanie speed vinthe same direction the drive shaft E. The liever E6 willV be at the position shown in Figure 40, for the 1:1 ratio.

A complete movement of thepistons i2V and lita to the left-hand ends of the cylinders -L and I -I will cause the pins 3S to travel further iai grooves as thejhelical d 35 are moved to the left in Figure l. The sY ne movement will cause the pins 39a. to travel from the longitudinal groove portions into the fourth helical groove portion 38g and to swing the right-hand thrust hearing lli from neutral position into one where it will be inclined to the left. Therefore, both the thrust bear' H and Hl will be inclined to the left and the device will be in Overdrive forward position. (EneV revolution of the drive sha-it will rotate thev driven shaft through two revolutions or there will be an overdrive, see

Figure el. j Y

It will therefore be seen as the pistons i2 tra Ymoved,--froin thev right-hand ends of the cylinders L? and L! to the left-hand ends; the transmission will rncve from reverse to neutrai for the sixth length of the cylinfcs' then to one-.3' f speed when the pistons was, reach the midway p nt; then to a one to one screw shafts ai Vratio between the drive and d 'iven shafts when the pistons are one-sixthl the distance from the left-hand ends of the cylinders; and finally to overdrive when the pistons reach the extreme left-hand Aends of thecylinders. The changing of the speeds from reverse, through neutral to overdrive is continuous and gradual as the leverV is swung over the dial Y$8 to effect` the desired speed change, see Figures 3T to di for the lever' St settings. Y i. f

flow of the fluid through'the passages 9i and 93,Y when the parts are inl O erdrive Vposias indicated by the arrows in Figure 30a, excepting-that the high pressure working flow and the low pressure idle now, will oe reversed. The high pressure Vworking flow will he in thatporpn of the passage 973 that eX- tends between the groups ci cylinders R and E. The high pressure will be equal in the compartpressure back. forth vor vibration flow of uid in that portion of the passage es that extends frorn the cylinders to the pipe .89.

The lov/pressure tion of the passage .that-extends between the groups of cylinders E and R. The low pressure vibrating Vflow will be in that portion of the passage si that extends from the cylinders R to the pipe t8. Y

The tlirust'of the girnbal J will give a counterclockwise thrust to the thrust plate Ei, and since ,this-is Va full stroke, it

will overcome the half There will also be a high i idlelow will ce in that por- -B and in the same direction,

"13 stroke thrust of the gimbal against the thrust 'plate H I in a clockwise direction. The cage D will therefore be rotated counterclockwise and fluid will be drawn off from the cylinders R and added to the cylinders E, thereby causing a secondary counterclockwise thrust to be applied to the Athrust plate H. The cage D and the driven shaft C will therefore rotate at a faster speed than the drive shaft B. ln fact the driven shaft C will rotate at twice the speed of the drive shaft Figure 41 indicates the position of the lever 66 when the parts "are in Overdrive.

From the foregoing description ofthe various parts of the device, the operation thereof may be vreadily understood. y

In setting forth the operation of the device, it is best to refer to the schematic Figures 37 and y4l, inclusive. Figure 37 illustrates that the lever 68 can be swung from the Reverse position shown, through three-fourths ofa circle around the dial 59 and back again, as indicated by the dot dash arrow lines I E58 in this gure. The lever $6 assumes the position shown in Figure 33, when the device is in-Neutral. Figure 39 shows the lever 66 swung still further in a counterclockwise position to indi- -cate Half Speed forward. Again, in Figure 40, the lever 66 has been swung farther around in a counter-clockwise direction into 1:1 ratio.r Finally, in Figure 4l, the lever 66 has completed its counter-clockwise swing and the parts are now in Overdrive position.

VIt is possible to swing the lever 65 into any intermediate position between its extremes of travel. In this way .the ,devicecan provide any desired speed ratio between the Reverse position shown in Figure 3'? and the Overdrive position illustrated in Figure 41. Applicant has already -set forthhow thesWinging of the lever Bev'will act on the uid control mechanism M, see Figures 52.5v to28, inclusive, so `,that the pistons 42 and Y42a', will be moved yinto the vvarious positions .indicated in Figures 37 to 4l, inclusive, for causing the device to operatein any of -theforward yor reverse speeds or to remain in Neutral. The moving of the pistonsliZ and 62a will act upon the cross head 37, see Figures 1 and 30, Vand .move the helical screws 34 and. 35, and rotate the worm sleeves 39,13! and IM,- H15.y The worm sleeves whenrotated will swing the thrust lplates H and .E-I! in ther manner schematically shown in Figures-,Sito 41, inclusive'andin ,thisgway the drivenshaft C will rotate atdif.- ferent speed ratios and in either respect to the drive shaft-J3. i,

.A more detailed descriptionof thejiuid `flow .in the cylindersor motorsdi and RV andfthegpassages .9 I and 93 .for the Reverse Speed-position, will vbe helpful..InFigure 30A, the entire; now is illustrated. l Et should he noted, that 'the driven shaft C has-two rows of rotatingprojecfftions. for each of the actors Evand Reand these projections act as4 valves forwthegpassagesy I -The valyevanes 93o arelshownlinFigure, 18, and Figures'Bl to 36, inclusive,,illustratehow-.these valve Yvanes rotate with the shaftC sopa-sto 'cover and uncover the passages Illin properse- 'quenc'e` l 1 7 r f The lhigh pressure uid workingiiowymoves fromthe compartment El in one of. the cylinders .in the motor along-the vpassage Sito the compartaient Rin oneof the,cylindersV inftherm'o- -tor; R. r The fluid;pressures willsfbe.equalin'the -compartmentsEl andi-'R3`zand .thelfno-vement?of to bring the parts directionr -with 'the vane I 4d to' force the uid from the compartment EI, will cause the high pressure fluid flow just mentioned. The fluid entering the compartment R3 will act on the vane I06a to swing it. The fluid temporarily forced from the compartment RI will enter the low pressure passage 93 and pipe 89, ready to return to the compartment RI as soon as the vane IUIa reverses its swing. A vibrating fluid flow will therefore be established infthat portion of the passage `53 that connects the compartment RI with the pipe 89.

. A low pressure idle fluid ow will be established in the portion of the passage 93 that connects the compartment R2 with the passage E4. The flow will be in the direction of the arrow. This flow Vwill merely'continue to ll the compartment E4 with fluidas the vane Hb swings to increase the size of this compartment and decrease the size of compartment E2. The uidin compartment E2 will be under high pressure and will be vforced from this compartment intorthev high pressure Aportion of the passage 9|.that leads to theicom'- partment R3. It will also be seen thatthe ilow pressure portion of passage 93 will feed fluid to the compartmentiEB to keep this compartment lled with fluid as the vane I 4a swings to enlarge this compartment and to reduce the capacity of thefcompartment El. I

' Figures 30 and 30A distinctly illustrate 'the diagonal' or crossover passages 9Ib in the driven shaftrC that place the compartments E3 and E4 in communication with each other and that place the compartments Elfand E2 in communication with eachother. One pair of vane valves 93o "f contro-1 the passages lI 0 in the fixed vanes 'I5 that form a wall of thercompa'rtments EI. and E4, and theother pair of vane valves'93c contro1 the other passages I0 inthe other fixed vanes vI 5 that -form a wall'of the compartments E2 and E3. The vane'valves 93e in each pair are 180 :apart as clearly shown in Figure 18. f

'At any: onelmoment `during the Reverse speed operation, the. compartments-EI and E2 have nhigh pressure fluid therein dueto the vanes :Mw and Mb reducing these compartments andthis iluid is directed through the passage 9i into'the .compartments R3 and Rllfor'swinging thevanes 'Illli'aY and '|'06b and imparting. rotation` through the Athrustplat'e fHI; to the driven. 'shaft-C; 5; At v'theend ofeach stroke of thevanesY Mal., Mb and '|0621' and' .1066; they :will be 'swung` in `thegopposite" direction: "The compartments E3 andsEd 4will'then become: high pressure fluid compartments andfthel compartments RI and R2 will likewise' reeeivevfthi's/:highAh pressure: fluid from; 4 the passage `93 and th'eicrossover passages 93a'and iFiguresf35and v3`6-indicate the flow ofuid-in the rotating motory when the parts are arrangedffor ail :1 ratio` between the driveshaft--B andthe driven sha-ft C. lThe thrustgplatefI-Il of the non-rotating motor R will be in neutral position, vsee Figure `40, and therefore the vanes H16 inthese cylinders willnot swing. Theanchored motor R will therefore draw no fluid into.. its .cylinders-and the rotating motor E will be free to impart 'directrotation to the'driven'shaft C from thedrive shaftB.' results in a Direct Drive 1or a"1:1jj`ratiog y' j y In thev Reverse position of Figure 37,'thejro'tatling motorE has its vanes Ill making a half stroke while thev nonrrotatin'ginotor R has its vanes IOjB making av full stroke; The motor E will tendto rttate'fthufivenishaft eeounteri-jcipekwisewhii'e the motor R will tend to rotate'the drivenfshaft stroke to its v'anes l5, 'the' vanes -greater leverage and resultant the dial 68,

Ml to `a position to close the pipes 4pistons' 52 and 42a will C,iclockwise. Since thehun-rotating motor R is imparting afullstroke to its vanes |06 and the rotating motor E is imparting only a half 136 'will have the the driven shaft C in a clockwise direction and therefore the parts will be in Reverse speed.V

. The control mechanism M for thepistons 42 and 42a is such that when the pistons have been moved in the cylinders L and L! to the corresponding to the position of the lever 56 on the shaft 44 will actuate the gears in the Vcontrol mechanism M for returning the valve l?. and lll. The

then cease the hydraulic transmission will operate at the set speed. It is possible to have the hydraulic trans- `of Reverse as shown in asshown 'in Figure 41.

Figures 31 to 34, inclusive, illustrate Vdiagrammatically the position of the various parts of the cylinders E when the device is in intermediate position or Half Speed forward position. The low pressure fluid fromV the motor R will be along the passage 9| to the motor E. The passage l0 to' the'top cylinder E in Figure 31 is uncovered by the Vane valve 93e and therefore the fluidwill flow into the compartment El as the vane'la swings to the left in Figure 30A. The flow is opposite to that shown as Reverseposition in Figure 30A.

The fluid in compartment E3 will be under high pressure because the swinging vane Ma will be continuously reducing the size of this Y compartment The Vhighv pressureV fluid forced 'out from theV compartment E3 will flow along the iiuid into or out of the compartments in these cylinders. TheV high pressure fluidwill flow along theY passage 93 to the vertical cylinders R, vand will act upon the vanes 106m and 106D to enlarge the compartments RA and R2, see VFigure 30A (keeping in mind that the vfrom that shown in Figure 30A, because the figure illustrates Reverse position). The vanes l' and '106D decrease the size of the compartments R3 and Ra and the fluid forced out from the compartment R4 will enter the crossover branch 9 ia to the passage'Sl while the fluid from the compartment R3 t l1 flow directlyY into the passage 9 I for entering the compartments El and E2.

' When the cylinders E have rotated v60" to the position shown in Figure 32, all four passages I0 leading to all'four cylinders E will be Ytemporarily uncovered .and the fluid flow will be as shown by the arrows. Further rotation of the cylinders E through another 60" is'illustrated in Figure 33. Here again all four passages I0 are open and theY fluid flow is as indicated by the arrows. Figure 34`shows the cylinders rotated throughA another 60 and the arrows again indicate the iluidow.

force will rotate position to move and this compartment exfluid'flow is opposite l Ymission operate at any speed between its extremes Figure 37 and Overdrive drive` shaft having a first I claim:

1.' A hydraulic transmission comprising: a bank of four radially extending cylinders, each lying in a plane 'disposed at right angles to the shaft axis and being spaced 90 apart from each other; a centrally disposed shaft mounted in each cylinder and being swingable about an axis coinciding with the longitudinal axis of the cylinder; a pair of outwardly extending and diametrically opposed varies mounted on each cylinder shaft and slidably contacting with the interior surface of the cylinder; a pair of diametrically opposed fixed vanes extending inwardly from the inner surface of each cylinder wall and slidably contacting with the cylinder shaft to form four compartments for each cylinder; a thrust plate swingable about an axis in the plane of the four'cylinders; gimbal mounting connections between the thrust plate and the cylinder shaftsY for causing the latter to swing their vanes in a predetermined manner according to the angular position of the thrust plate; a driven shaft having fluid conveying passages adapted to communicate with the four compartments in each cylinder; means for supplying fluid to the passages; valve-like members on the shaft for controlling the fluid flow between the passages and the cylinder compartments; a cage connected to and rotatable with the driven shaft; a second bank of four radially extending stationary cylinders, each lying in a plane disposed at right angles to the driven'shaft axis and being spaced 90 apart; said second bank of cylinders having centrally disposed shafts; vanes on the cylinder shafts in the second bank of cylinders; stationary vanes on the cylinder walls on the second bank of cylinders; a second thrust plate swingable about an axis that lies in the plane of the second bank of cylinders; a second gimbal mounting connection between the second thrust plate and the second set of cylinder Y Y shafts for causing the latter to swing their vanes in a Y predetermined manner according to the angular position of the second Ythrust plate; the fluid conveying passages of the driven shaft also communicating With the compartments in the second set of cylinders; additional valve-like members on the shaft for controlling theiiuid ow between the passages and the compartments inthe second set of cylinders; and means carried by the cage and operatively connected to the thrustv plates for swinging them into different angular positions for altering Ythe. speed of ro-V tation of the driven shaft with respect to the drive shaft.

2. The combination as Yset Y means is operatively connected to the thrust plate swinging'means for Yholding the thrust plates at the angle determined by the setting of the manually controlled speed setting means. lg

3. A hydraulicrtransmissioncomprising: a drive shaft having a first bank of four radially extending and diametric'allyopposed vanes mounted oneach cylinder shaft and slidably'contactingY with the interior surface of the cylinder; a pair of diametricallyfoppose'd fixed vanes extending Y inwardly from the'inner surface 'of'.each cylinder wall and slidably contacting vwith the cylinder.

forth in claim r1;Y Vand in which manually Ycontrolled speed setting 17 shaft to form four compartments for each cylinder; a thrust plate swingable about an axis that lies in the plane of the four cylinders; gimbal mounting connections between the thrust plate and the cylinder shafts for causing the latter to swing their vanes in a predetermined manner according to the angular position of the thrust plate; a driven shaft having uid conveying passages adapted to communicate with the four compartments in each cylinder; means for supplying fluid to the passages and relieving the passages of excess fluid; valve-like members on the shaft for controlling the fluid ow between the passages and the cylinder compartments; a stationary sleeve enclosing a portion of the driven shaft and having a second bank of four radially extending stationary cylinders, each lying in a second plane disposed at right angles tol the driven shaft axis and being spaced 90 apart; each cylinder in the second bank of cylinders being provided with an oscillatable shaft, diametrically opposed rvanes on the shaft, and inwardly extending stationary vanes that lie between the inner cylindrical surface and oscillatory shaft, in the same manner as with the rst bank of cylinders; a second thrust plate swingable about an axis that lies in the second plane; a second gimbal mounting connection between the second thrust plate and the second set of cylinder shafts for causing the latter to swing their vanes in a predetermined manner according to the angular position of the second thrust plate; the fluid conveying passages of the driven shaft also communicating with the compartments in the sec ond set of cylinders; additional valve-like members on the shaft for controlling the fluid flow between the passages and the compartments in the second set of cylinders; a cage rotatable with the driven shaft; means carried by the cage and operably connected to the thrust plates for swinging them into different predetermined angulaipositions for altering the speed of rotation between the drive and driven shafts and the direction of rotation between the two shafts.

4. The combination as set forth in claim 3; and in which manually controlled speed setting means is operatively connected to the thrust plate swinging means for holding the thrust plates at the angle determined by the setting of the manually controlled speed setting means.

No references cited. 

